package com.noahsloan.nutils.streams;

import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * Normal behavior. Just adds a method to reflect that the end of stream has
 * been reached without disturbing the underlying stream.
 * 
 * @author noah
 * 
 */
public class IsFinishedInputStream extends FilterInputStream {

    private boolean finished;

    public IsFinishedInputStream(InputStream in) {
        super(in);
    }

    @Override
    public int read() throws IOException {
        return check(super.read());
    }

    @Override
    public int read(byte[] b) throws IOException {
        return check(super.read(b));
    }

    @Override
    public int read(byte[] b, int off, int len) throws IOException {
        return check(super.read(b, off, len));
    }

    /**
     * Checks for end of stream, returning the value passed in.
     * 
     * @param read
     * @return
     */
    private int check(final int read) {
        if (read == -1) {
            finished = true;
        }
        return read;
    }

    /**
     * Marks as finished and calls super.close.
     */
    @Override
    public void close() throws IOException {
        finished = true;
        super.close();
    }

    /**
     * 
     * @return true if EOS was reached or close was called.
     */
    public boolean isFinished() {
        return finished;
    }
}
